- DNS Server: a computer running DNS sever software
- zone: a container for a single domain that gets filled with records
- record: a line in the line zone data that maps an FQDN to an IP address
- systems running DNS server software store the DNS information
- when a system needs to know the IP address for a specifc FQDN, it queries the DNS server listed in the TCP/IP configuration
- Authoritative DNS server: a simple network usually has one DNS server for the entire network
- job is to make sure that all the other name servers are updated for changes
- a DNS server has a signle zone that lists all the host names on the domain and their corresponding IP addresses
- a single DNS domain may have a single authoritative DNS server but a number of other DNS servers
Name Resolution
- a web browser must resolve the name to the web server's IP address to make a connection to that web server
- can be resolved in three ways
- broadcasting
- consulting the locally stored HOSTS text file
- contacting a DNS server
- to broadcast, the host sends a message to all the machines on the network
- works for small networks
- limited because it cannot provide name resolution across routers
- routers do not forward broadcast messages to other networks
- a HOSTS file lists the names and addresses of machines on a network
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